<template>
	<view>
		<my-search @click="gotoSearch"></my-search>
		<view class="scroll-view-container">
			<!-- 左侧滑动区 -->
			<scroll-view class="left-scroll-view" scroll-y="true" :style="{height: wh + 'px'}">
				<view class="left-scroll-view-item" :class="{ active: active === idx }" @click="activeChange(idx)"
				v-for="(item, idx) in cateList" :key="item.cat_id">
					{{item.cat_name}}
				</view>
			</scroll-view>
			<!-- 右侧滑动区 -->
			<scroll-view scroll-y="true" :style="{height: wh + 'px'}" :scroll-top="scrollTopDis">
				<view class="cate-level2" v-for="(item, idx) in cateLevel2" :key="item.cat_id">
					<!-- 二级分类标题 -->
					<view class="cate-level2-title">
						/ {{ item.cat_name }} /
					</view>
					<view class="cate-level3-list">
						<!-- 三级分类 -->
						<view class="cate-level3-item" v-for="(item2, idx) in item.children" :key="item2.cat_id"
						 @click="gotoGoodList(item2)">
							<image :src="item2.cat_icon"></image>
							<text>{{ item2.cat_name }}</text>
						</view>
					</view>
				</view>
			</scroll-view>
		</view>
	</view>
</template>

<script>
	import badgeMix from '@/mixins/tarbar-badge.js'
	export default {
		mixins: [badgeMix],
		data() {
			return {
				wh: 0,
				cateList: [],
				active: 0,
				cateLevel2: [],
				scrollTopDis: 0
			};
		},
		onLoad() {
			const sysInfo = uni.getSystemInfoSync()
			// 屏幕可用高度
			this.wh = sysInfo.windowHeight - 50
			this.getCateList()
		},
		methods: {
			// 获取分类列表
			async getCateList() {
				// 发起请求
				const { data: res } = await uni.$http.get('/api/public/v1/categories')
				// 判断是否获取失败
				if (res.meta.status !== 200) return uni.$showMsg()
				// 转存数据
				this.cateList = res.message
				// 为二级分类赋值
				this.cateLevel2 = this.cateList[0].children
			},
			// 更改一级分类
			activeChange(idx) {
				this.active = idx
				this.scrollTopDis = this.scrollTopDis === 0 ? 1 : 0
				this.cateLevel2 = this.cateList[idx].children
			},
			// 跳转商品列表
			gotoGoodList(item) {
				uni.navigateTo({
					url: '/subpkg/goods_list/goods_list?cid=' + item.cat_id
				})
			},
			gotoSearch() {
				uni.navigateTo({
					url: '/subpkg/search/search'
				})
			}
		}
	}
</script>

<style lang="scss">
	.scroll-view-container {
		display: flex;

		.left-scroll-view {
			width: 120px;

			.left-scroll-view-item {
				line-height: 60px;
				background-color: #f7f7f7;
				text-align: center;
				font-size: 12px;

				// 激活项的样式
				&.active {
					background-color: #ffffff;
					position: relative;

					// 渲染激活项左侧的红色指示边线
					&::before {
						content: ' ';
						display: block;
						width: 3px;
						height: 30px;
						background-color: #c00000;
						position: absolute;
						left: 0;
						top: 50%;
						transform: translateY(-50%);
					}
				}
			}
		}
	}
	
	.cate-level2-title {
		font-size: 12px;
		font-weight: bold;
		text-align: center;
		padding: 15px 0;
	}
	
	.cate-level3-list {
		display: flex;
		flex-wrap: wrap;
		
		.cate-level3-item {
			display: flex;
			flex-direction: column;
			justify-content: center;
			align-items: center;
			margin-bottom: 10px;
			width: 33.33%;
			image {
				width: 60px;
				height: 60px;
				background-image: url('https://img95.699pic.com/photo/40174/5313.jpg_wh860.jpg');
				background-size: cover;
			}
			text {
				font-size: 12px;
			}
		}
	}
</style>
